Refactor, add minimum Node version, replace SRI link

README.md

@@ -1,20 +1,21 @@
 # get-sri
 
+[![Node.js Version][node-badge]][node-url]
 [![Travis CI - Build Status][travis-badge]][travis-url]
 [![AppVeyor CI - Build Status][appveyor-badge]][appveyor-url]
 [![Coveralls - Code Coverage Status][cov-badge]][cov-url]
 [![JavaScript Style Guide][jsstd-badge]][jsstd-url]
 [![PRs Welcome][pr-badge]][pr-url]
 
-Generates the [**SRI**][sri-url] [*(Subresource Integrity)*][sri-url] of the given string 
+Generates the [**SRI**][sri-url] [*(Subresource Integrity)*][sri-url] hash of the given string 
 to use as the **SRIs of CDN files** without publishing the content to CDN 
 *(e.g. when generating the readme file before release and publish)*.
 
 With `get-sri`, you can just simply generate the `sha256-j7UhB[...]5ni2s=` part of the `integrity` attribute
 for `<link>` and `<script>` elements, e.g.: 
 
 ```html
-<script src="https://cdn.mycustom.com/javascript-file-from-cdn.min.js" 
+<script src="https://example.com/example-framework.js" 
         integrity="sha256-j7UhB8zxegHMV59uYb38Ho75sqloISge2+fsjN5ni2s=" 
         crossorigin="anonymous"></script>
 ```
@@ -46,16 +47,15 @@ getSRI('... file content as string ...', getSRI.SHA256, true) // 'sha256-OXPgIuk
 ## Contribution
 
 **Any contribution is appreciated**. To get going, check out the 
-[**contribution guidelines**](CONTRIBUTING.md) and the 
-[**development guide**](DEVELOPMENT.md). 
-
-***Thank you, have fun!***
+[**contribution guidelines**](CONTRIBUTING.md). ***Thank you, have fun!***
 
 ## License
 
 [MIT](LICENSE.md) @ [Richard Szakacs](https://www.github.com/richardszkcs)
 
 
+  [node-badge]:     https://img.shields.io/badge/Node-4+-brightgreen.svg?longCache=true&style=flat
+  [node-url]:       https://travis-ci.org/ntbx/get-sri
   [travis-badge]:   https://travis-ci.org/ntbx/get-sri.svg?branch=master
   [travis-url]:     https://travis-ci.org/ntbx/get-sri
   [appveyor-badge]: https://ci.appveyor.com/api/projects/status/09qmd4yk9arxyeph?svg=true
@@ -68,5 +68,5 @@ getSRI('... file content as string ...', getSRI.SHA256, true) // 'sha256-OXPgIuk
   [jsstd-url]:      https://standardjs.com
 
   [pr-badge]:       https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square
-  [sri-url]:        https://hacks.mozilla.org/2015/09/subresource-integrity-in-firefox-43
+  [sri-url]:        https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity
   [pr-url]:         CONTRIBUTING.md